1,424 research outputs found
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Performance evaluation of urban traffic management and ITS: The Rome case study
In order to cope with their growing traffic problems, cities throughout the world deploy Intelligent Transport System (ITS) applications in various fields of urban networks. The decision making process for the installation of ITS is a dialogue between the political instance of the municipalities and the planners. The strategic concept and the detailed planning are undertaken by transportation experts in the respective planning authorities and is based on a vast variety of measurements and evaluations (Reed et al., 1993). The decision for funding the systems however is taken on a political level and is based on the consideration of expected benefits, economic aspects but also public debates and controversies. It is obvious that this dialogue within an inhomogeneous group of stakeholders needs a common basis for the consideration of benefits of ITS as a counterpart to the often obvious costs.In order to deliver this common basis of discussion, a transparent methodology to calculate and present the benefits of ITS has to be elaborated.This methodology should support the decision making process in several aspects:? to identify best practice applications already operational in similar cases in other cities;? to decide on the installation of the system on a technical and a political level;* Technische Universität München†IUAV University of Venice‡ Imperial College London§ Technion, Israel Institute of Technology2. to monitor the performance of the deployed application over a longer period of time;to weigh the investment and operational cost compared to thebenefits of the system. Several solutions to this problem were proposed within the EU FP7 project CONDUITS (2009 - 2011). They included the elaboration of a set of Key Performance Indicators (KPI) targeting different categories of ITS and providing a single, measurable value for their benefit. The following paper gives an overview of the definition process for the KPI, explains their function and gives an example for the calculation of the KPI based on real-life data provided by the city of Rome
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Urban traffic management and Intelligent Transport Systems: A European perspective
The objective of this paper is to establish the state-of-the-art of urban traffic management in Europe, with a particular focus on Intelligent Transport Systems (ITS), using data collected from 34 cities directly with the help of a purpose-developed questionnaire. Several areas of traffic management are covered, such as: general statistics of the transport systems, organisational structures, monitoring and forecasting, provision of traffic information and urban traffic control. Special focus is also given to demand management, traffic control centres, public transport and parking. Broadly summarising the results, it can be said that a wide range of traffic management technologies and policies are used in Europe. It is encouraging to see that strategic plans and traffic control centres are generally present in the participating cities, as well as facilities for public transport, ITS technologies and real-time public transport information. In addition, most cities have cycling infrastructure, pedestrian zones and alternative mobility schemes, as well as good policies for weaker population categories, such as the elderly, the jobless and the disabled. While the study has some limitations with respect to the reliability of the data provided by the cities, mainly originating from different definitions or from the absence of data all together, it can be considered a fairly good overview of the state-of-the art of urban traffic management in Europe
Evaluation of different methods to estimate the transfer of immunity in donkey foals fed with colostrum of good IgG quality: A preliminary study
The aims of the present study were to evaluate the correlation between IgG Serum Radial Immunodiffusion (SRID), Electrophoresis Gamma Globulins (EGG), Electrophoresis Total Protein (ETP) and the serum total protein (TP) analyzed by refractometry and by a dry chemistry analyzer (Biuret) and to estimate serum IgG concentrations using serum TP. A total of 36 samples collected at four different times (birth, 6, 12, 24 hours after birth) from nine Amiata donkey foals were evaluated with SRID, EGG, ETP, serum TP Biuret and refractometry. SRID IgG concentration increased significantly over time until T12. Serum TP analyzed with refractometry, electrophoresis and Biuret showed a statistically significant difference between T0 and T6 vs T12 and T24. A good or strong correlation was found between different tests performed. Equations to quantify serum IgG were created and can be used for estimating the donkey foals’ serum IgG in the first day of life. Serum TP refractometry showed a high correlation with SRID IgG (0.91) which may be a particularly useful and economic instrument to estimate the transfer of immunity in donkey foals during the first day of life
Particle-in-cell simulations of circularly polarised Alfvén wave phase mixing: A new mechanism for electron acceleration in collisionless plasmas
In this work we used Particle-In-Cell simulations to study the interaction of circularly polarised Alhén waves with one dimensional plasma density inhomogeneities transverse to the uniform magnetic field (phase mixing) in collisionless plasmas. In our preliminary work we reported discovery of a new electron acceleration mechanism, in which progressive distortion of the Alfvén wave front, due to the differences in local Alfvén speed, generates an oblique (nearly parallel to the magnetic field) electrostatic field. The latter accelerates electrons through the Landau resonance. Here we report a detailed study of this novel mechanism, including: (i) analysis of broadening of the ion distribution function due to the presence of Alfvén waves; and (ii) the generation of compressive perturbations due to both weak non-linearity and plasma density inhomogeneity. The amplitude decay law in the inhomogeneous regions, in the kinetic regime, is demonstrated to be the same as in the MHD approximation described by Heyvaerts & Priest (1983, A&A, 117, 220)
Radiographic parameters of the digit in a cohort population of amiata donkeys
Background: The most common musculoskeletal conditions reported in donkeys are related to the foot. Radiographic examinations are clinically important in the diagnosis of foot abnormalities and are commonly used. However, few studies have been conducted to establish the normal radiographic appearance of a donkey’s foot. Aim: To determine the radiographic features of the front digit in healthy Amiata donkeys. Methods: Radiographic examinations were performed on 56 forefeet of 28 Amiata donkeys. Three radiographic views of each front foot were taken: lateromedial, dorsopalmar and dorso-65°proximal/palmarodistal oblique. Seventeen angular and linear radiographic parameters and the crena solearis were evaluated in all forefeet, and 18 morphometric parameters were evaluated in 16 out of 56 forefeet. Statistical analysis was carried out on all the measures assessed. Results: The radiographic appearance of the forefoot was ascertained, and data were reported as median ± standard error, minimum and maximum values. No statistical differences were obtained between the right and left forefeet. Conclusion: The normal baseline parameters of the forefeet of Amiata donkeys were recorded and described and compared with other donkey breeds and horses. The findings highlighted that the donkey breed affects the radiographic parameters of the digit
Evaluation of jennies' colostrum: IgG concentrations and absorption in the donkey foals. A preliminary study
Immunoglobulin type G (IgG) concentration both in jennies' colostrum and in serum of donkey foals are mostly unknown in the first 24 h after delivery. The aims of the present study were to evaluate the IgG concentrations of colostrum during the first 24 h of lactation of Amiata jennies, the absorption of colostrum and the weekly body weight gain of the donkey foals. IgG concentrations were assessed in the jennies' colostrum and in the serum of donkey foals. Colostrum was collected in 9 jennies ready after delivery, and at 6, 12, 24 h after foaling from both halves. Serum was collected at the same sampling times from 9 donkey foals. Donkey foals were weighted at birth and then weekly until the 28th days of life. Temporal changes of IgG concentrations in dam's colostrum and in donkey foal serum were analyzed by a linear regression model and a general linear model, respectively. Results showed that colostrum IgG concentration were similar between the left and the right half. Colostrum IgG concentrations decreased continuously throughout the time in all jennies by 0.0244 Log10 mg/mL per hour. Serum IgG concentrations in donkey foals at birth was significantly lower compared to other times. No correlation was found between the colostrum IgG concentrations and the average weekly body weight gain of the donkey foal. The pattern of colostrum IgG levels in jennies and serum IgG concentration in donkey foals seem to be similar to what reported for equine. However, the donkey foals seem to be less agammaglobulinemic at birth compared to the horse foal. The pattern and both serum and colostrum concentrations evaluated in the Amiata donkeys were slightly different from results reported in other donkey breeds, underlying the importance of setting references specific to breed
Ultrasonographic Appearance of Elbow Joints in a Population of Amiata Donkeys
Ultrasound (US) is a well-established technique for investigating joint diseases in horses, complementary to radiography. Few studies have been performed on the ultrasonographic aspect of the elbow joint in horses and no reports are available on donkeys. The aim of this study is to describe the ultrasonographic appearance of the elbow joint in healthy donkeys. Descriptive cohort study included 34 elbow joints, which were evaluated in 17 donkeys. Inclusion criteria included no lameness or musculoskeletal diseases in the donkeys. The structures evaluated were the lateral and medial collateral ligaments, ulnaris lateralis proximal tendon, distal biceps brachii tendon, triceps brachii tendon, and the articular space. For each structure, one good-quality image was recorded. The structures were retrospectively assessed for echogenicity, fiber orientation, bone appearance, and shape. The prevalence of the visualized structures was calculated. Cohen Îş coefficient was calculated for the repeatability (intraoperator agreement), the reproducibility (interoperator agreement), and the influence of the operator's experience in US examination. The US appearance of the structures was described. Statistical analysis showed scarce-to-moderate agreement concerning the repeatability and mostly scarce-to-good agreement concerning the reproducibility of the US examination; finally, low-to-discrete agreement concerning the operator's experience. Technical difficulties precluded an accurate description of the medial collateral ligament. The healthy animals included were limited. The US examination of the elbow joint in donkeys were similar to the features reported in horses. Individual experience partially influences the execution and the assessment of the US images
Evaluation of a questionnaire to detect the risk of developing ESGD or EGGD in horses
Equine gastric ulcer syndrome (EGUS) affects various categories of horses worldwide. This syndrome is now divided into two different diseases, based on the presence of lesions on either the squamous (Equine Squamous Gastric Disease, ESGD) or the glandular (Equine Glandular Gastric Disease, EGGD) mucosa. Diagnosis is based on the evaluation of the presence of gastric lesions with gastroscopic examination. As a gastroscopy can be considered expensive by clients, therapy is started often on the basis of clinical signs only. The aim of this study was to validate a questionnaire to detect the risk of developing ESGD or EGGD. The owners of 418 horses that were submitted to gastroscopic evaluation were asked to answer a questionnaire on risk factors for ESGD and EGGD. Horses were divided into three groups based on the results of the questionnaire and their risk of developing gastric lesions. In our population the survey was not useful to detect the presence and the severity of the lesions detected during gastroscopic examination, however answers to some of the questions did correlate with the development of gastric lesions. The questionnaire could therefore be a useful tool to evaluate the risk of ESGD or EGGD. Having owners periodically complete the survey could also make them more aware of changes in the conditions of the horses that could lead to gastric lesions. This could then help them seek advice from veterinarians on how to manage this potential ris
Spin chirality on a two-dimensional frustrated lattice
The collective behavior of interacting magnetic moments can be strongly
influenced by the topology of the underlying lattice. In geometrically
frustrated spin systems, interesting chiral correlations may develop that are
related to the spin arrangement on triangular plaquettes. We report a study of
the spin chirality on a two-dimensional geometrically frustrated lattice. Our
new chemical synthesis methods allow us to produce large single crystal samples
of KFe3(OH)6(SO4)2, an ideal Kagome lattice antiferromagnet. Combined
thermodynamic and neutron scattering measurements reveal that the phase
transition to the ordered ground-state is unusual. At low temperatures,
application of a magnetic field induces a transition between states with
different non-trivial spin-textures.Comment: 7 pages, 4 figure
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